The DocBook table layout supports two models: CALS and HTML.
In the CALS table model, you can specify column widths using the
colwidth attribute of the associated colspec element. The
values can be fixed or proportional. By default, when you insert, drag and drop, or copy/paste
a column, the value of the colwidth attribute is 1*.
Also the colsep and rowsep attributes are
supported. These control the way separators are painted between the table cells.
Figure: CALS table in DocBook
